It's easy to slap a label on your partner, like: "You're just an introvert," or "You're such an extrovert." But Dr. Matt Townsend said really understanding what is behind those personality descriptions can help you really understand the people around you. He explained how a lot of us think that extroverts like people and introverts don't, but it's actually not really about people. He gave five science-based reasons we tend to be either extroverts, introverts or ambiverts.